Disconnecting central hot water and using electric showers to avoid colonization of the water system by Legionella pneumophila: an 11-year study.

Legionella spp. can be difficult to control in hospitals. The objective of this study was to describe an 11-year experience with the use of electric showers in the control of Legionella pneumophila. From June 1989 to March 1990 there was an outbreak of pneumonia caused by L. pneumophila in a 20-bed renal transplant unit in a university-associated tertiary-care hospital. Control measures included hyperchlorination, heating and flushing of the water system with limited results. In November 1993 the central hot water was disconnected and water for bathing was heated using electric showers. From January 1992 to June 1995 water was collected from showers and water faucets and cultured for L. pneumophila every two weeks. Surveillance cultures were then collected every month until May 1999. During this seven-year surveillance period, 1115 samples of water were cultured. Water cultures were positive on 24 of 429 occasions (without cases of legionellosis) during the pre-shower period (22 months). In the post-shower period (67 months) only one of 686 cultures was positive. Subsequently there have been no new cases of nosocomial pneumonia by L. pneumophila although surveillance continues. In conclusion, disconnecting the central hot water was effective in avoiding colonization of the water system by L. pneumophila. Heating was possible by using electric showers, which are effective, easy to maintain and cheap.

In vitro activity of fluoroquinolones (gatifloxacin, levofloxacin and trovafloxacin) and seven other antibiotics against Streptococcus pneumoniae.

In recent years, the level of resistance of S. pneumoniae to beta-lactam and/or macrolides has increased around the world including some countries in South America. Because of this resistance, it is necessary to test the therapeutic alternatives for treating this pathogen, including the newer quinolones. This study was carried out in order to compare the in vitro activity of fluoroquinolones gatifloxacin, levofloxacin and trovafloxacin, to penicillin G, amoxicillin, amoxicillin-clavulanate, cufuroxime sodium, ceftriaxone, azithromycin and clarithromycin, against 300 strains of S. pneumoniae. Of the 300 samples tested, 18.6% were not susceptible to penicillin (56 strains) and 7% (21 strains) were resistant to the second generation cephalosporin. Among the macrolides, resistance ranged from 6.7% for clarithromycin to 29.6% for azithromycin. Susceptibility to the newer quinolones was 100% including the 56 strains not susceptible to penicillin. Among the 10 antibiotics evaluated, the fluoroquinolones gatifloxacin, levofloxacin, and trovafloxacin displayed high levels of in vitro activity against S. pneumoniae.

Detection of mycobacteria in the bloodstream of patients with acquired immunodeficiency syndrome in a university hospital in Brazil.

This study was done to determine the occurrence of mycobacteria in the bloodstreams of patients with fever and advanced AIDS in a Brazilian hospital. We also verified the capability of an automated method for recovering these bacteria. During a period of 19 months, 254 patients with AIDS were evaluated. Blood cultures were generally submitted in pairs and drawn separately. Blood cultures were processed by the BACTEC 460TB System (Becton Dickinson Microbiology Systems, Sparks, MD), using the Bactec 13A media (Becton Dickinson Microbiology Systems, Sparks, MD). Of the 530 vials submitted, 77 (14.5%) from 41 (16%) patients were positive. Mycobacterium avium complex was recovered from 45 (58.4%) of the 77 positive vials, corresponding to 22 (53.6%) patients with positive blood cultures. The average time to detect Mycobacterium avium complex was 15 days. Mycobacterium tuberculosis was recovered from 26 (33.8%) of the 77 positive vials, corresponding to 15 (36.6%) patients with positive blood cultures, with an average detection time of 24 days. Other species of mycobacteria were recovered from 6 (7.8%) of the 77 vials, corresponding to 4 (9.8%) patients. M.avium complex was fairly prevalent (8.7%) in severely ill patients with AIDS in our hospital. M. tuberculosis was also an important (6.0%) agent of systemic bacterial infections in these patients. The rapid diagnosis of mycobacteremia was possible with the implementation of this automated technology.

In vitro susceptibility of gram-positive cocci isolated from skin and respiratory tract to azithromycin and twelve other antimicrobial agents.

This study was conducted to evaluate the activity of azithromycin in comparison to 12 other antibacterial agents against recent isolates obtained consecutively from patients with respiratory tract or skin infections, from January to July, 2000. A total of 717 Gram-positive cocci were analyzed in this study and the following species were studied: Staphylococcus aureus (n=576), beta-hemolytic streptococci (n=115), and Streptococcus pneumoniae (n=26). Susceptibility testing was carried out by the disk diffusion method and interpreted according to NCCLS breakpoints. The activity of azithromycin was compared to erythromycin, clindamycin, chloramphenicol, ciprofloxacin, ofloxacin, oxacillin, penicillin, ceftriaxone, tetracycline, trimethoprim/sulfamethoxazole, teicoplanin, and vancomycin. Of the 26 S. pneumoniae isolates recovered from the respiratory tract, 5 (19.2%) were intermediate resistant to penicillin. All of these strains were susceptible to chloramphenicol, ofloxacin, and vancomycin, and 24 (92%) were also susceptible to azithromycin, clindamycin, and erythromycin. Among the 67 beta-hemolytic streptococci strains isolated from the respiratory tract, 66 (99%) were susceptible to azithromycin, erythromycin, clindamycin, and ofloxacin. All 48 beta-hemolytic streptococci strains isolated from skin were susceptible to azithromycin and clindamycin, 47 (98%) were susceptible to erythromycin, and 46 (96%) were susceptible to ofloxacin. Of the 576 strains of S. aureus, 253 (43.9%) were isolated from the respiratory tract and 323 (56.1%) from skin. Among S. aureus isolates from the respiratory tract and skin, 46 (18%) and 78 (24%), respectively were resistant to oxacillin. Isolates from the respiratory tract and skin showed the same percentage of resistance (36%) to azithromycin. These in vitro results suggest that azithromycin can be a therapeutic option for treatment of infections caused by these bacteria since the newer macrolides have several distinct advantages over erytromycin including improved oral bioavailability, longer half-life allowing once or twice daily administration, higher tissue concentrations and less gastrointestinal adverse effects.

Environmental contamination by multidrug-resistant Acinetobacter baumannii in an intensive care unit.

Contamination in an intensive care unit caused by multidrug-resistant Acinetobacter baumannii complex (MRAB)-colonized patients was evaluated using environmental and patient cultures. MRAB occurred in 21% of patients' cultures, 2.1% of 513 areas surrounding MRAB-patients, and one of 372 common areas. No transmission to other patients occurred. Barrier precautions and ethanol disinfection may prevent dissemination.

Evaluation of the in vitro activity of 9 antimicrobials against bacterial strains isolated from patients in intensive care units in brazil: MYSTIC Antimicrobial Surveillance Program.

Multi-resistant bacterial strains are increasingly prevalent in hospital environments. Bacterial resistance is an important problem, especially for practitioners in intensive care units (ICUs) because of the selective pressure on the prevalent bacteria in these environments. The MYSTIC (Meropenem Yearly Susceptibility Test Information Collection) study has been monitoring the performance of carbapenems and other antibiotics in different hospitals for at least 3 years. The in vitro activities of meropenem, imipenem, ceftazidime, cefepime, cefotaxime, ciprofloxacin, piperacilin/tazobactam, gentamicin, and tobramycin were compared against 452 recent clinical aerobic isolates. The isolates consisted of 19 species of Gram-negative bacteria (n=290) including K. pneumoniae (n=49), E. coli (n=48), A. baumannii (n=47), Enterobacter spp. (n=41), and P. aeruginosa (n=33) and 9 species of Gram-positive bacteria (n=162) including Staphylococcus aureus (n=63), Enterococcus faecalis (n=22), Streptococcus pneumoniae (n=22) and coagulase negative Staphylococci (n=21). All isolates were collected from ICU patients. Minimal inhibitory concentrations (MICs) were determined by Etest methodology, using standardized and controlled procedures. Meropenem and imipenem showed the lowest MIC(90) for all species tested. Gram-negative isolates showed the following overall resistance percentages to the other 7 drugs: tobramycin (43.1%), cefotaxime (38.6%), gentamicin (34.1%), ceftazidime (31.7%), ciprofloxacin (25.5%), piperacillin/tazobactam (26.9%), and cefepime (18.6%). Carbapenems were the most active drugs overall and only P. aeruginosa presented some degree of resistance (18.2%). We also evaluated the production of extended spectrum beta-lactamase (ESBL) among all Enterobacteriaceae members (n=176) by Etest/ESBL strip. ESBL production was detected in 51 strains (29.0%). Among them, Klebsiella pneumoniae was the most prevalent at 59.2%, followed by Enterobacter spp. (19.5%) and E. coli (14.6%). The high level of resistance against several antimicrobials and the alarming rate of ESBL production may restrict therapeutic choice to the carbapenems in this selected group of patients.

Nosocomial infections caused by multiresistant Pseudomonas aeruginosa.

A case-control study was done to evaluate factors associated with nosocomial infections by multiresistant Pseudomonas aeruginosa (MRPA). Results showed that MRPA was associated with the use of immunosuppressive and antimicrobial drugs. Five typing methods indicated that the MRPA infections were due to multiple strains rather than a single strain.

Candida parapsilosis fungemia associated with implantable and semi-implantable central venous catheters and the hands of healthcare workers.

A cluster of six cases of fungemia among hematology, bone marrow transplant, and oncology patients was investigated in a case-control study (18 controls). The use of implantable and semi-implantable central venous catheters was significantly associated with cases (p = 0.016). The hands of three healthcare workers (HCWs) were positive for Candida parapsilosis. Electrophoretic karyotyping showed two profiles among patients and HCWs, and five among six unrelated strains. The profiles of two HCWs matched the ones of the patients they had handled. The patients' strains were moderate or strong slime producers, whereas none of the HCWs' were strong producers. In conclusion, our results indicated the occurrence of an outbreak C. parapsilosis fungemia related to long-term central venous catheters in which the hands of HCWs were implicated. The amount of slime production might be associated with the pathogenicity of the strains.

In vitro activity of ampicillin-sulbactam against clinical multiresistant Acinetobacter baumannii isolates.

We evaluated the in vitro activity of ampicillin-sulbactam in comparison with that of broad-spectrum antimicrobial agents against Acinetobacter baumannii isolates. Two hundred and twelve clinical isolates collected between January 1993 and March 1995 from two tertiary hospitals located in São Paulo, Brazil were tested for susceptibility by the disk diffusion method against several broad-spectrum antimicrobial agents, including imipenem, ciprofloxacin, ceftazidime, aztreonam, amikacin, and polymyxin B. All strains were susceptible to polymyxin B. The second most active compound was the combination ampicillin-sulbactam (88% susceptibility). Only 79% of the isolates were susceptible to imipenem. Ciprofloxacin was active against 60 (28%) and amikacin against 34 (16%) isolates. Ceftazidime was the most active cephalosporin; however, only 9% of the isolates were susceptible to this compound. Both aztreonam and ampicillin alone showed very poor activity against this species (1% susceptibility). The prevalence of severe infections due to A. baumannii is increasing very rapidly in the tertiary hospitals of São Paulo and there are very few options for the treatment of these infections. Polymyxin B is invariably in vitro active against this species; however, this compound can cause severe side effects and is not commercially available for intravenous use in Brazil and in several other countries. Our results indicated that the combination ampicillin-sulbactam may be an alternative drug for the treatment of infections due to multiresistant A. baumannii; however, further studies are necessary to evaluate the clinical role of this compound for the treatment of severe infections.

An outbreak of multiresistant Acinetobacter baumanii in a university hospital in São Paulo, Brazil.

A case-control (46 cases, 23 controls) study was done to determine risk factors for an outbreak of a multiresistant Acinetobacter baumanii (only susceptible to colistin) in a university hospital. The use of antecedent antibacterials and intubation were independent risk factors. No common source was found. With control measures, the outbreak resolved gradually.

Epidemiologic investigation of an outbreak of coagulase-negative Staphylococcus primary bacteremia in a newborn intensive care unit.

Infections due to coagulase-negative Staphylococcus (CNS) are an ever-increasing nosocomial problem, particularly in the pediatric population. The authors describe a cluster of three primary bloodstream infections due to CNS in a newborn intensive care unit that occurred between November 23 and December 2, 1992. Two children died as a direct consequence of the bacteremia; at autopsy, one had a large bacteria-containing thrombus extending from the insertion site of a central catheter to the superior vena cava. The children were placed in isolation, and the nursing and medical staff were given topical nasal mupirocin. Plasmid analysis performed later disclosed three different blood isolates that also were different from any of the staff's nasal isolates. The authors concluded that molecular methods such as plasmid analysis are important tools in identifying true outbreaks and can prevent needless interventions, such as those during this cluster.

Electric showers as a control measure for Legionella spp. in a renal transplant unit in São Paulo, Brazil. Legionellosis Study Team.

After an outbreak of legionnaires' disease Legionella pneumophila serogroup 1 in a renal transplant unit in São Paulo, Brazil, periodic hyperchlorination and flushing of pipes were instituted as control measures. These were only partially effective as every two to five months water cultures turned positive or new cases of the disease occurred. In November 1993 the hot water was disconnected from the unit and small, plastic electric showers were installed in each bathroom. Over a period of 12 months water from showers and taps was cultured for Legionella spp. every two weeks. On only one occasion was a water culture positive for L. pneumophila from a sink tap. No water sample obtained from showers was positive during the study period. No cases of legionnaires' disease occurred. We considered the use of electric showers an inexpensive and effective method of controlling the problem of Legionella spp. in the water system of our renal transplant unit.

Avaliaçäo da sensibilidade a teicoplanina e vancomicina, em Staphylococcus aureus e estafilococos coagulase negativos / Evaluation of teicoplanin and vancomycin susceptibility in Staphylococcus aureus and coagulase-negative staphylococci

Membros do gênero staphylococcus säo os patógenos mais comuns encontrados no ambiente hospitalar e vêm adquirindo resistência múltipla aos antimicrobianos. OBJETIVO. Avaliar as atividades inibitórias in vitro da teicoplanina e da vancomicina frente a 195 amostras de estafilococos isolados de processos infecciosos significativos, provenientes de pacientes internados. MÉTODOS. foram estudadas 100 amostras de Staphylococcus aureus, sendo a metade representada por cepas resistentes à oxacilina, e 95 amostras de estafilococos coagulase negativos (ECN), sendo 44 cepas resistentes à oxacilina, que foram submetidas às provas de sensibilidade pela técnica da diluiçäo en ágar e da difusäo do disco em ágar. RESULTADOS. Todas as cepas (100 por cento) foram sensíveis à vancomicina; as amostras de S. aureus apresentaram MIC90 DE 0,5µg/mL, enquanto que os ECN mostraram MIC90 de 1,0µg/mL. Para a teicoplanina, 98,5 por cento das amsotras se mostraram sensíveis; o MIC90 foi de 0,5µg/mL para as cepas de S. aureus, de 2,0 µg/mL para as cepas de ECN (sensíveis à oxacilina) e de 8,0µg/mL para as cepas de ECN (resistentes à oxacilina). CONCLUSÄO. Do ponto de vista microbiológico, os resultados demonstraram o alto potencial de ambas as drogas como agentes terapêuticos para infecçöes causadas por estafilococos multiresistentes de origem hospitalar

[Teicoplanin and vancomycin susceptibility in Staphylococcus aureus and coagulase-negative staphylococci]. / Avaliação da sensibilidade à teicoplanina e vancomicina, em Staphylococcus aureus e estafilococos coagulase negativos.

Members of the genera Staphylococcus are the most common pathogens found in the hospital environment and they are acquiring resistance to multiple drugs. PURPOSE--To evaluate the in vitro activity of teicoplanin and vancomycin against 195 strains of staphylococci isolated from in-patients. METHODS--One hundred strains of Staphylococcus aureus (50% methicillin-resistant) and 95 strains of coagulase-negative staphylococci (46.3% strains methicillin-resistant) were tested by the agar dilution and the disk diffusion techniques. RESULTS--All strains (100%) were susceptible to vancomycin, S. aureus strains presented MIC90 of 0.5 microgram/mL whereas strains of coagulase-negative staphylococci showed MIC90 of 1.0 microgram/mL. For teicoplanin, 98.5% of the strains were susceptible. MIC90 values were 0.5 microgram/mL for S. aureus strains, 2.0 micrograms/mL for coagulase-negative methicillin-susceptible staphylococci strains and 8.0 micrograms/mL for coagulase-negative methicillin-resistant staphylococci strains. CONCLUSION--From the microbiological point of view, the results showed a high potential for both drugs as therapeutic agents in staphylococcal infections due to multiresistant strains of hospital origin.

An outbreak of nosocomial Legionnaires' disease in a renal transplant unit in São Paulo, Brazil. Legionellosis Study Team.

From June 1989 to March 1990 there were eight cases of Legionnaires' disease caused by Legionella pneumophila serogroup 1 in a renal transplant unit. There were seven cases of pneumonia and one case of pleural effusion. A study was conducted to identify the source of the outbreak. Legionella anisa was cultured from tap water. Twenty-seven staff members of the unit were serologically tested and antibody titres were positive in two. The probable source of infection was the potable water system. Control measures were hyperchlorination and heating of the water, after which there were no further cases during 5 months' follow up. We believe this is the first reported Legionnaires' disease outbreak in Latin America.

Dengue with haemorrhage and shock in Jakarta, Indonesia.

Pediatric patients with fever and haemorrhage were studied in Jakarta, Indonesia between May 1973 and January 1974. Eighty-one of 104 demonstrated unequivocable evidence of dengue with clinical findings similar to those reported associated with dengue haemorrhagic fever in Thailand. The majority of patients had extremely high antibody titers against dengue measured by both hemagglutination-inhibition and by plaque reduction neutralization tests and all four types of dengue virus were isolated. Eight of the patients died.